diff options
| -rw-r--r-- | drivers/tty/tty_io.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 2e166a1be2b7..66d6bcc24c7e 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1344,19 +1344,24 @@ static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) * @driver: the driver for the tty * @idx: the minor number * - * Return the tty, if found or ERR_PTR() otherwise. + * Return the tty, if found. If not found, return NULL or ERR_PTR() if the + * driver lookup() method returns an error. * - * Locking: tty_mutex must be held. If tty is found, the mutex must - * be held until the 'fast-open' is also done. Will change once we - * have refcounting in the driver and per driver locking + * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. */ static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, struct inode *inode, int idx) { + struct tty_struct *tty; + if (driver->ops->lookup) - return driver->ops->lookup(driver, inode, idx); + tty = driver->ops->lookup(driver, inode, idx); + else + tty = driver->ttys[idx]; - return driver->ttys[idx]; + if (!IS_ERR(tty)) + tty_kref_get(tty); + return tty; } /** @@ -2081,16 +2086,20 @@ retry_open: } if (tty) { + mutex_unlock(&tty_mutex); tty_lock(tty); + /* safe to drop the kref from tty_driver_lookup_tty() */ + tty_kref_put(tty); retval = tty_reopen(tty); if (retval < 0) { tty_unlock(tty); tty = ERR_PTR(retval); } - } else /* Returns with the tty_lock held for now */ + } else { /* Returns with the tty_lock held for now */ tty = tty_init_dev(driver, index); + mutex_unlock(&tty_mutex); + } - mutex_unlock(&tty_mutex); tty_driver_kref_put(driver); } |